The American Bulldog has ONE written standard in the UKC. The American Bulldog was first recognized by the UKC  on January 1, 1999.  American Bulldog UKC Written Standard Illustrated By: Julie Pengilley The UKC has ONE show ring for the American Bulldog. Both types show against each other in ONE ring.

The original Bulldog, however, was preserved by working class immigrants who brought their working dogs with them to the American South. Small farmers and ranchers used this all-around working dog for many tasks. By the end of World War II, however, the breed was almost extinct. Mr. John D. Johnson, a returning war veteran, decided to resurrect this breed. Along with Alan Scott and several other breeders, Johnson began carefully to breed American Bulldogs, keeping careful records and always with an eye for maintaining the breed's health and working abilities. 

Because of the many different types of work this breed can do, several distinct lines evolved, each emphasizing the traits needed to do a specific job. The best known lines are usually referred to as the Johnson and Scott types. The Johnson dogs are more massive, with a larger, broader head and shorter muzzle, and a definite undershot bite. The Scott dogs were somewhat lighter in musculature and bone than the Johnson dogs, with a less Mastiff-like head. Today, however, most American Bulldogs have crosses to two or more of these lines and are not as easily distinguishable. 

The modern American Bulldog continues to serve as an all-purpose working dog; a fearless and steady guard dog; and a loyal family companion. 

General Appearance: 
The American Bulldog is a powerful, athletic short-coated dog, strongly muscled, and well boned. The body is just slightly longer than tall. The head is large and broad with a wide muzzle. Ears are small to medium in size, high set, and may be drop, semi-prick, rose, or cropped. The tail may be docked or natural. The American Bulldog comes in solid colors, white with colored patches, and brindle. Gender differences are well expressed in this breed, with males typically larger and more muscular than females. Honorable scars resulting from field work are not to be penalized. The American Bulldog should be evaluated as a working dog, and exaggerations or faults should be penalized in proportion to how much they interfere with the dog's ability to work. 

Characteristics: 
The essential characteristics of the American Bulldog are those which enable it to work as a hog and cattle catching dog, and a protector of personal property. These tasks require a powerful, agile, confident dog with a large head and powerful jaws. The American Bulldog is a gentle, loving family companion who is fearless enough to face an angry bull or a human intruder. Note: It is common for young American Bulldogs to be somewhat standoffish with strangers and judges should not penalize this. By the time the dog is around 18 months of age, however, the breed's normal confidence asserts itself.  Disqualifications: Viciousness or extreme shyness; cowardice. 

Head: 
The head is large and broad giving the impression of great power. When viewed from the side, the skull and muzzle are parallel to one another and joined by a well-defined stop. The stop is very deep and abrupt, almost at a right angle with the muzzle. Despite the depth of the stop, the forehead is wider than it is high. 

SKULL -- The skull is large, flat, deep, and broadd between the ears. Viewed from the top, the skull is square. There is a deep median furrow that diminishes in depth from the stop to the occiput. Cheek muscles are prominent. 

MUZZLE -- The muzzle is broad and thick with a veryy slight taper from the stop to the nose. The length of the muzzle is equal to 35 to 45 percent of the length of the head. Lips are moderately thick but not pendulous. The chin is well defined and must neither overlap the upper lip nor be covered by it. 

Wry Jaw

Wry Jaw

A Correct / Straight Jaw Line

Flews too pendulous

TEETH -- The American Bulldog has a complete set oof large, evenly spaced, white teeth. The preferred bite is undershot with the inside of the lower incisors extending in front of the upper incisors up to ¼ inch. A scissors bite is acceptable. A level bite and extreme undershot bite are considered faults to the degree that the bite interferes with the dog's ability to work. Teeth are not visible when the mouth is closed. Worn teeth or broken teeth are acceptable. 
Disqualification: Overshot. 

NOSE -- The nose is large with wide, open nostrills. The nose may be any color but darker pigment is preferred. 

Black Nose Correct Color preferred

Black Nose w/ Pink Allowed Color

Black Nose w/ Pink, Poor Pigment

Grizzle/ Liver Nose

Grizzle Nose w/ Pink

Pink Nose Very poor pigment

EYES -- Eyes are medium in size, round, and set wwell apart. All colors are acceptable but brown is preferred. Haw is not visible. Dark eye rims are preferred. 
Faults: Very visible haws. 

Good Eye Color  &  Good Pigment

Poor Eye Pigment

Poor Eye Pigment  (Liver /Grizzle) Green Eye Color

2 Color Eyes Brown & Blue

Poor Eye Pigment & Visible Haw - Fault

EARS -- Ears may be cropped but natural ears are preferred. Natural ears are small to medium in size, high set, and may be drop, semi-prick, or rose. 

Drop ears: The ears are set high, level with the upper line of the skull, accentuating the skull's width. At the base, the ear is just slightly raised in front and then hangs along the cheek. The tip is slightly rounded. When pulled toward the eye, the ear should not extend past the outside corner of the eye. 

Semi-prick ears: Same as drop ears except that only the tips of the ears drop forward. 

Rose ears: Rose ears are small and set high on the skull. 
Fault: Hound ears. 

Correct Ear Set and length

Ear Set Too Low Hound Ears

Ear Set Too High Bat like.

Rose Ear Set Acceptable

Corpped Ears

Ear's way  too short. APBT like.

Ears, Boston Terrier like.

Neck: 
The neck is where the American Bulldog exerts power to bring down livestock. The neck must be long enough to exert leverage, but short enough to exert power. The neck is muscular and, at its widest point, is nearly as broad as the head, with a slight arch at the crest, and tapering slightly from shoulders to the head. A slight dewlap is acceptable. 
Faults: Neck too short and thick; thin or weak neck. 

Forequarters: 
The shoulders are strong and well muscled. The shoulder blade is well laid back and forms, with the upper arm, an apparent 90-degree angle. The tips of the shoulder blades are set about 2 to 3 finger-widths apart. 

The forelegs are heavily boned and very muscular. The elbows are set on a plane parallel to the body, neither close to the body nor turned out. Viewed from the front, the forelegs are perpendicular to the ground or may, especially in a dog with a very broad chest, incline slightly inward. The pasterns are short, powerful, and slightly sloping when viewed in profile. Viewed from the front, the pasterns are straight. 

Body: 
The chest is deep and moderately wide with ample room for heart and lungs. The ribs are well sprung from the spine and then flatten to form a deep body extending at least to the elbows, or lower in adult dogs. The topline inclines very slightly downward from well-developed withers to a broad, muscular back. The loin is short, broad, and slightly arched, blending into a moderately sloping croup. The flank is moderately tucked up and firm. 
Serious faults: Swayback; sloping topline. 

Nice Back, Good Angulation

Sway Backed Alittle Straight Stifled

High in the rear end or low in the front shoulder, how ever you want to look at it.

Straight Stifled No Angulation in Rear Legs.

Hindquarters: 
The hindquarters are well muscled and broad. The width and angulation of the hindquarters is in balance with the width and angulation of the forequarters. The thighs are well developed with thick, easily discerned muscles. The lower thighs are muscular and short. Viewed from the side, the rear pasterns are well let down and perpen-dicular to the ground. Viewed from the rear, the rear pasterns are straight and parallel to one another. 
Faults: Cowhocks; open hocks. 
Serious faults: Narrow or weak hindquarters. 

Narrow Hips And Cow Hocked

Cow Hocked in Rear Legs

Cow Hocked in Rear Legs

Straight Legs

Feet: 
The feet are round, medium in size, well arched, and tight. 
Fault: Splayed feet. The seriousness of this fault is based on the amount of splay in the feet. 

Splay Toes - Fault

Crooked Toes - Fault

Knucking Over

Tight Feet / Toes

Tail: 
The American Bulldog may have a natural or a docked tail, but the natural tail is preferred. The natural tail is very thick at the base, and tapers to a point. The tail is set low. A "pump handle" tail is preferred but any tail carriage from upright, when the dog is excited, to relaxed between the hocks is acceptable. 
Serious fault: Tail curled over the back; corkscrew tail; upright tail when the dog is relaxed. 

Correct Tail Set

Docked Tail

Tail Too Short

Tail Too Long

Rat Tail ( too thin)

Curled over back Serious Fault

Screw Tail Cosmetic Fault

Coat: 
The coat is short, close, and stiff to the touch. 
Disqualifications: Long or wavy coat. 

Long Haired AB - Disqualified

Long Fuzzy Tail - Disqualified

Long Haired AB with littermate, that is short hair.

Color: 
Any color, color pattern, or combination of colors is acceptable, except for solid black, solid blue, and tricolor (white with patches of black and tan). Some dark brindle coats may appear black unless examined in very bright light. A buckskin color pattern, where the base of the hair is fawn and the tips are black, may also appear solid black. A judge should not disqualify an American Bulldog for black color unless the dog has been examined in sunlight or other equally bright light. 
Disqualifications: Solid black or blue with no white markings; tricolor (white with patches of black and tan). 

Solid Black AB - Disqualified

Solid Blue AB - Disqualified

Tri-Colored AB - Disqualified

Height and Weight: 
The American Bulldog must be sufficiently powerful and agile to chase, catch, and bring down free-ranging livestock. Dogs capable of doing this come in a rather wide range of height and weight. Males are typically larger with heavier bone and more muscle than females. Both sexes, however, should have a well-balanced overall appearance. 

Desirable height in a mature male ranges from 22 to 27 inches; in a mature female, from 20 to 25 inches. Desirable weight in a mature male ranges from 75 to 125 pounds; in a mature female, from 60 to 100 pounds. 

Gait: 
When trotting, the gait is effortless, smooth, powerful and well coordinated, showing good reach in front and drive behind. When moving, the backline remains level with only a slight flexing to indicate suppleness. Viewed from any position, legs turn neither in nor out, nor do feet cross or interfere with each other. As speed increases, feet tend to converge toward center line of balance. Poor movement should be penalized to the degree to which it reduces the American Bulldog's ability to perform the tasks it was bred to do. 

Disqualifications: 
Unilateral or bilateral cryptorchid. Viciousness or extreme shyness. Unilateral or bilateral deafness. Cowardice. Overshot. Long or wavy coat. Albinism. Solid black or blue with no white markings. Tricolor (white with patches of black and tan).